The Patron's Lunch will be attended by members of nearly 700 charities supported by the Queen at The Mall, which runs from the palace to Trafalgar Square, on Sunday, June 12 next year.
She will be joined by her husband Prince Philip, the Duke of Edinburgh, and grandsons Princes William and Harry at the party, organised by Peter Phillips also the Queen's grandson and director of Sports Entertainment Ltd, a global events agency that came up with the idea.
The street party will be the culmination of a weekend of national events next summer to celebrate the Queen's official 90th birthday.
The Mall will be lined with picnic tables for the street party, during which guests will enjoy a hamper-style lunch.
Of the 10,000 tickets, most will be allocated to guests from the Queen's charities and organisations, but around 1,000 will be made available for a public ballot.
Members of the public will also be able to share in the festivities at live sites situated in nearby Green Park and St James's Park.
The not-for-profit event will raise money for the new Patron's Fund, which will be used to support specific initiatives and projects run by the Queen's charities.
Peter Phillips, the son of Princess Anne the monarch's daughter, said the celebration would emphasise the Queen's support for her charities. "We want to reflect the service she's given to all her organisations and charities," he said. Speaking of his grandmother, he said, "She's obviously been kept abreast through her office about all the developments, and the times I've had the chance to talk to her she's been excited by it".
The Queen is patron of a wide range of organisations, including children's charity Barnardo's, Battersea Dogs and Cats Home, and Great Ormond Street Hospital. The Patron's Organisations is a collection of more than 600 organisations across 17 different sectors and are represented across the UK and the Commonwealth.
The organisers hope communities around the country will be inspired to stage patron's lunches in their own areas and raise money for local projects. Queen Elizabeth II was born on April 21 but as per royal tradition the British monarch's birthday is celebrated during the summer month of June.
A service of thanksgiving - which will be attended by the Queen and Prince Philip - will be held at St Paul's Cathedral on Friday, June 10 next year. The following day, the traditional Trooping the Colour ceremony will be staged in Horse Guards Parade in central London.